What is the range characteristic of electrons in a medium?

The range characteristic of electrons in a medium is finite due to their interactions with matter, which primarily include ionization and excitation of atoms. As electrons travel through a medium, they lose energy as they collide with atomic electrons, leading to a gradual slowing down until they eventually come to a stop. This process is influenced by several factors, including the density and atomic number of the medium, as well as the initial energy of the electrons.

In practice, this means that there is a specific distance that electrons can effectively penetrate before their energy is depleted entirely. This limited range is a crucial consideration in clinical applications such as radiation therapy, where electrons are used to treat superficial tumors while sparing surrounding healthy tissue. A finite range allows planners to carefully design treatment plans that maximize the dose to the tumor while minimizing exposure to adjacent normal tissues.